?? jpg.c
字號(hào):
#include <stdio.h>#include <stdlib.h>#ifndef __ECOS#include <memory.h># include <malloc.h>#endif#include <setjmp.h>#include "jpeglib.h"#include "jpg.h"struct my_error_mgr { struct jpeg_error_mgr pub; /* "public" fields */ jmp_buf setjmp_buffer; /* for return to caller */};typedef struct my_error_mgr * my_error_ptr;METHODDEF(void)my_error_exit (j_common_ptr cinfo){ /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */ my_error_ptr myerr = (my_error_ptr) cinfo->err; /* Always display the message. */ /* We could postpone this until after returning, if we chose. */ (*cinfo->err->output_message)(cinfo); /* Return control to the setjmp point */ longjmp(myerr->setjmp_buffer, 1);}int unpack_jpg(jpg_info_t* jinfo){ struct jpeg_decompress_struct cinfo; /* We use our private extension JPEG error handler. * Note that this struct must live as long as the main JPEG parameter * struct, to avoid dangling-pointer problems. */ struct my_error_mgr jerr; /* More stuff */ JSAMPARRAY buffer; /* Output row buffer */ int row_stride; /* physical row width in output buffer */ cinfo.err = jpeg_std_error(&jerr.pub); jerr.pub.error_exit = my_error_exit; jpeg_create_decompress(&cinfo); jpeg_memory_src(&cinfo, jinfo->jpg_buffer, jinfo->jpg_buffer_length); jpeg_read_header(&cinfo, TRUE); jpeg_start_decompress(&cinfo); /* JSAMPLEs per row in output buffer */ row_stride = cinfo.output_width * cinfo.output_components; /* Make a one-row-high sample array that will go away when done with image */ buffer = (*cinfo.mem->alloc_sarray) ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1); jinfo->width=cinfo.output_width; jinfo->height=cinfo.output_height; jinfo->jpg_surface=(unsigned char*)malloc(jinfo->width*jinfo->height*3); while (cinfo.output_scanline < cinfo.output_height) { unsigned char* temp_src_buffer; unsigned char* temp_des_buffer; jpeg_read_scanlines(&cinfo, buffer, 1); temp_src_buffer=(unsigned char*)(*buffer); temp_des_buffer=jinfo->jpg_surface+jinfo->width*(cinfo.output_scanline-1)*3; memcpy(temp_des_buffer,temp_src_buffer,row_stride); } jpeg_finish_decompress(&cinfo); jpeg_destroy_decompress(&cinfo); return 0;}int destroy_jpg(jpg_info_t* jinfo){ if (jinfo->jpg_surface!=NULL) { free(jinfo->jpg_surface); } return 0;}#ifndef EXIT_FAILURE /* define exit() codes if not provided */#define EXIT_FAILURE 1#endif/* * Create the message string table. * We do this from the master message list in jerror.h by re-reading * jerror.h with a suitable definition for macro JMESSAGE. * The message table is made an external symbol just in case any applications * want to refer to it directly. */#define JMESSAGE(code,string) string ,const char * const jpeg_std_message_table[] = {#include "jpg.h" NULL};/* * Error exit handler: must not return to caller. * * Applications may override this if they want to get control back after * an error. Typically one would longjmp somewhere instead of exiting. * The setjmp buffer can be made a private field within an expanded error * handler object. Note that the info needed to generate an error message * is stored in the error object, so you can generate the message now or * later, at your convenience. * You should make sure that the JPEG object is cleaned up (with jpeg_abort * or jpeg_destroy) at some point. */METHODDEF(void)error_exit (j_common_ptr cinfo){ /* Always display the message */ (*cinfo->err->output_message) (cinfo); /* Let the memory manager delete any temp files before we die */ jpeg_destroy(cinfo);}/* * Actual output of an error or trace message. * Applications may override this method to send JPEG messages somewhere * other than stderr. */METHODDEF(void)output_message (j_common_ptr cinfo){ char buffer[JMSG_LENGTH_MAX]; /* Create the message */ (*cinfo->err->format_message) (cinfo, buffer); /* Send it to stderr, adding a newline */ fprintf(stderr, "%s\n", buffer);}/* * Decide whether to emit a trace or warning message. * msg_level is one of: * -1: recoverable corrupt-data warning, may want to abort. * 0: important advisory messages (always display to user). * 1: first level of tracing detail. * 2,3,...: successively more detailed tracing messages. * An application might override this method if it wanted to abort on warnings * or change the policy about which messages to display. */METHODDEF(void)emit_message (j_common_ptr cinfo, int msg_level){ struct jpeg_error_mgr * err = cinfo->err; if (msg_level < 0) { /* It's a warning message. Since corrupt files may generate many warnings, * the policy implemented here is to show only the first warning, * unless trace_level >= 3. */ if (err->num_warnings == 0 || err->trace_level >= 3) (*err->output_message) (cinfo); /* Always count warnings in num_warnings. */ err->num_warnings++; } else { /* It's a trace message. Show it if trace_level >= msg_level. */ if (err->trace_level >= msg_level) (*err->output_message) (cinfo); }}/* * Format a message string for the most recent JPEG error or message. * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX * characters. Note that no '\n' character is added to the string. * Few applications should need to override this method. */METHODDEF(void)format_message (j_common_ptr cinfo, char * buffer){ struct jpeg_error_mgr * err = cinfo->err; int msg_code = err->msg_code; const char * msgtext = NULL; const char * msgptr; char ch; boolean isstring; /* Look up message string in proper table */ if (msg_code > 0 && msg_code <= err->last_jpeg_message) { msgtext = err->jpeg_message_table[msg_code]; } else if (err->addon_message_table != NULL && msg_code >= err->first_addon_message && msg_code <= err->last_addon_message) { msgtext = err->addon_message_table[msg_code - err->first_addon_message]; } /* Defend against bogus message number */ if (msgtext == NULL) { err->msg_parm.i[0] = msg_code; msgtext = err->jpeg_message_table[0]; } /* Check for string parameter, as indicated by %s in the message text */ isstring = FALSE; msgptr = msgtext; while ((ch = *msgptr++) != '\0') { if (ch == '%') { if (*msgptr == 's') isstring = TRUE; break; } } /* Format the message into the passed buffer */ if (isstring) sprintf(buffer, msgtext, err->msg_parm.s); else sprintf(buffer, msgtext, err->msg_parm.i[0], err->msg_parm.i[1], err->msg_parm.i[2], err->msg_parm.i[3], err->msg_parm.i[4], err->msg_parm.i[5], err->msg_parm.i[6], err->msg_parm.i[7]);}/* * Reset error state variables at start of a new image. * This is called during compression startup to reset trace/error * processing to default state, without losing any application-specific * method pointers. An application might possibly want to override * this method if it has additional error processing state. */METHODDEF(void)reset_error_mgr (j_common_ptr cinfo){ cinfo->err->num_warnings = 0; /* trace_level is not reset since it is an application-supplied parameter */ cinfo->err->msg_code = 0; /* may be useful as a flag for "no error" */}/* * Fill in the standard error-handling methods in a jpeg_error_mgr object. * Typical call is: * struct jpeg_compress_struct cinfo; * struct jpeg_error_mgr err; * * cinfo.err = jpeg_std_error(&err); * after which the application may override some of the methods. */GLOBAL(struct jpeg_error_mgr *)jpeg_std_error (struct jpeg_error_mgr * err){ err->error_exit = error_exit; err->emit_message = emit_message; err->output_message = output_message; err->format_message = format_message; err->reset_error_mgr = reset_error_mgr; err->trace_level = 0; /* default = no tracing */ err->num_warnings = 0; /* no warnings emitted yet */ err->msg_code = 0; /* may be useful as a flag for "no error" */ /* Initialize message table pointers */ err->jpeg_message_table = jpeg_std_message_table; err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1; err->addon_message_table = NULL; err->first_addon_message = 0; /* for safety */ err->last_addon_message = 0; return err;}#define JPEG_INTERNALS#include "jpegint.h"#define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */#ifndef NO_GETENV#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */extern char * getenv JPP((const char * name));#endif#endif/* * Some important notes: * The allocation routines provided here must never return NULL. * They should exit to error_exit if unsuccessful. * * It's not a good idea to try to merge the sarray and barray routines, * even though they are textually almost the same, because samples are * usually stored as bytes while coefficients are shorts or ints. Thus, * in machines where byte pointers have a different representation from * word pointers, the resulting machine code could not be the same. *//* * Many machines require storage alignment: longs must start on 4-byte * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc() * always returns pointers that are multiples of the worst-case alignment * requirement, and we had better do so too. * There isn't any really portable way to determine the worst-case alignment * requirement. This module assumes that the alignment requirement is * multiples of sizeof(ALIGN_TYPE). * By default, we define ALIGN_TYPE as double. This is necessary on some * workstations (where doubles really do need 8-byte alignment) and will work * fine on nearly everything. If your machine has lesser alignment needs, * you can save a few bytes by making ALIGN_TYPE smaller. * The only place I know of where this will NOT work is certain Macintosh * 680x0 compilers that define double as a 10-byte IEEE extended float. * Doing 10-byte alignment is counterproductive because longwords won't be * aligned well. Put "#define ALIGN_TYPE long" in jconfig.h if you have * such a compiler. */#ifndef ALIGN_TYPE /* so can override from jconfig.h */#define ALIGN_TYPE double#endif/* * We allocate objects from "pools", where each pool is gotten with a single * request to jpeg_get_small() or jpeg_get_large(). There is no per-object * overhead within a pool, except for alignment padding. Each pool has a * header with a link to the next pool of the same class. * Small and large pool headers are identical except that the latter's * link pointer must be FAR on 80x86 machines. * Notice that the "real" header fields are union'ed with a dummy ALIGN_TYPE * field. This forces the compiler to make SIZEOF(small_pool_hdr) a multiple * of the alignment requirement of ALIGN_TYPE. */typedef union small_pool_struct * small_pool_ptr;typedef union small_pool_struct { struct { small_pool_ptr next; /* next in list of pools */ size_t bytes_used; /* how many bytes already used within pool */ size_t bytes_left; /* bytes still available in this pool */ } hdr; ALIGN_TYPE dummy; /* included in union to ensure alignment */} small_pool_hdr;typedef union large_pool_struct * large_pool_ptr;typedef union large_pool_struct { struct { large_pool_ptr next; /* next in list of pools */
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